基于三维地质模型的西咸新区地下空间开发适宜性评价

Geological Suitability for Urban Underground Space Development in Xixian New Area Based on 3D Modeling

地下空间开发地质适宜性评价是合理进行地下空间开发、降低开发地质风险的重要手段。传统的评价方法没有考虑地下空间复杂的垂向变化,因而无法满足越来越精确的地下空间规划要求。本文以西咸新区沣东沣西为例,结合该区地质地貌背景、工程地质特征、水文地质条件、不良地质作用以及地下空间开发现状等特点,建立地下空间开发地质适宜性评价因子体系;利用三维精细化剖分的评估单元为载体,综合使用多种三维空间分析方法从多要素地质模型中定量或定性提取各项指标,运用层次分析法模型开展研究区地下空间开发适宜性评价。评价结果表明:研究区60m以浅地下空间开发利用条件优越,总体适宜开发建设。浅层空间易受文物保护区、地面水体、活动断裂影响,中层空间受城市建成区既有设施及地下构筑物影响较大,深部地下空间主要受断裂影响。该方法能够精细刻画地下空间在垂向上的差异,评估过程与结果能够立体透明化表达,能够定性、定量地为地下空间开发利用提供辅助决策,以达到资源保护优先、协同开发的开发利用格局。

Geological suitability evaluation of underground space development is an important means of rationally developing underground space and reducing geological risk.Traditional evaluation methods do not consider the complex vertical changes of underground space,and cannot meet the requirements of much accurate underground space planning.Taking the Xixian New Area as an example,this work established a geological suitability evaluation factor system of underground space development.Based on the 3D urban geology model with multiple elements,various 3D spatial analysis methods were comprehensively used to extract various indexes quantitatively or qualitatively from the model.The analytic hierarchy process(AHP)model was used to evaluate the suitability of underground space development in Xixian New Area.The evaluation results show that the conditions in the study area are suitable for development and construction.The shallow layer was easily affected by cultural relics,water bodies and faults,the middle layer was greatly affected by existing facilities and underground structures,and the deep underground space was mainly affected by faults.The evaluation results can provide strong support for the development,utilization,planning and construction of underground space in Xixian New Area.